For me at least, Both of these games fall into the "Generic Bioware" category, We have our protagonist who has to save the world/universe/small puppy/whatever but to do so he needs to gather a small group of boring, self absorbed individuals who feel it necessary to tell you there life story when ever you ask them what the time is.
Once said protagonist has gathered these individuals and equipped them with new trousers he can then embark on his/her quest. This usually entails running through linear worlds/towns/buildings and sucking up to once for your followers enough that they may give you a blow-job.
Oh and throw in a couple of moral dilemmas and a plot twist around 3/4 of the way through the game and you have every Bioware fanboi itching to hand over their money.
Back on topic though I much preferred Mass Effect to KotOR, I found the story to be (a little) less predictable and the combat and game play just felt more...Natural.